Re: NULL vs. Empty String
От | David Wheeler |
---|---|
Тема | Re: NULL vs. Empty String |
Дата | |
Msg-id | Pine.LNX.4.21.0103140851320.12837-100000@theory обсуждение исходный текст |
Ответ на | Re: NULL vs. Empty String ("Oliver Elphick" <olly@lfix.co.uk>) |
Список | pgsql-general |
On Wed, 14 Mar 2001, Oliver Elphick wrote: > You could write a rule for each table/column that would substitute > NULL for ''. > > However, the concept is all wrong. NULL means "I don't know what > this value is". '' means "I know that this value is an empty string". > Furthermore, having NULLs in columns means you have to be careful > to use ternary logic for every condition (because NULL=x is neither > true nor false). And On Wed, 14 Mar 2001, Steven Lembark wrote: > Postgress is doing what you want it to -- see anything CJ Date > has written in the last 20 years. you are better off inserting > a default value of '' than NULL -- otherwise you have no idea > what joins mean. I completely agree with you two that PostgreSQL does The Right Thing (TM) vs. what Oracle does. Thus, perhaps I should shift the focus of my queries to the mod_perl list, since I think it makes sense that empty form fields submitted from a web page should show up in Perl as undefined (and therefore will be inserted into Postgres as NULL) rather than as empty strings. Thanks for the feedback. David
В списке pgsql-general по дате отправления: